Fuel injection pump conversion arrangement and method



Dec. 3, 1968 CHMURA ET AL 3,413,924

FUEL INJECTION PUMP CONVERSION ARRANGEMENT AND METHOD Filed April 11. 1967 2 Sheets-Sheet l INVENTORSZ THEODORE s. CHMURA BY MAX VQIGT ATTYS,

' Dec. 3, 1968 5, HM R ET AL 3,413,924

FUEL INJECTION PUMP CONVERSION ARRANGEMENT AND METHOD Filed April 11. 1967 7 2 Sheets-Sheet 2 FIGB.

INVENTORSI THEODORE S. CIHMURA MAX HM VOIGT United States Patent ABSTRACT OF THE DISCLOSURE In a single plunger distributor type fuel injection pump, a conversion arrangement and method for halving the number of operational pump outlet ports by plugging or otherwise eliminating certain of the outlet ports and by providing slot means in the plunger to direct the fuel which would normally be pumped toward the blocked ports either to the fuel supply sump or to the operational ports.

The present invention relates generally to fuel injection pumps of the single plunger distributor type and relates more particularly to a method and arrangement for halving the number of operational pump outlets to adapt a pump for use with an engine having fewer cylinders than that for which it was originally designed. For example, by the relatively simple arrangement and method of the invention, a pump designed and constructed for use with a four cylinder four stroke cycle engine to be driven at engine speed may suitably be used with a two cylinder four stroke cycle engine driven at one-half engine speed or with a two cylinder two stroke cycle engine driven at engine speed. Similarly, a six cylinder pump may be adapted for use with a three cylinder engine of either two or four strokes per cycle.

The advantages of such a conversion arrangement are apparent when the substantial design and development costs of fuel injection equipment are considered. By adapting a single pump design to three or four different engine applications, not only are the development and fabrication costs per engine design materially reduced, but the maintenance burden is lightened as Well.

The present conversion arrangement and method involve essentially the plugging or elimination of half of the pump outlet ports and the providing of one or more slots in the pump plunger in addition to the distributor slot to direct the fuel which normally would be pumped toward the plugged ports either to the fuel supply sump or to the operational outlet ports. The inoperative ports may either be plugged as in the conversion of a completed pump, or may simply be left undrilled during the fabrication of the pump. In either instance, fuel which would normally be pumped to the inoperative port locations during the rotation of the plunger will, in the present invention, be carried by means of the added slot means in the plunger either to the operational ports or to the fuel supply sump,. depending upon which embodiment of the invention is chosen.

It is accordingly a primary object of the present invention to provide in a single plunger distributor type fuel injection pump a conversion arrangement and method for halving the number of operational pump outlet ports to adapt the pump for use with an engine having half the number of cylinders as that for which the pump was designed.

A further object of the invention is to provide a conversion arrangement and method as described which involve only simple inexpensive modifications of the plunger andthe pump hydraulic head. 9

Additional objects and advantages of the invention will be more readily apparent from the following detailed deice scription of embodiments thereof when taken together with the accompanying drawings in which:

FIG. 1 is a partial plan view of a. fuel injection pump embodying the conversion arrangement of the present invention;

FIG. 2 is a partial sectional view of the pump including the hydraulic head taken along line 22 of FIG. 1;

FIG. 3 is a partial sectional view taken along line 3-3 of FIG. 1 showing additional details of the pump hydraulic head;

FIG. 4 is a fragmentary sectional view taken along line 4-4 of FIG. 1 showing one of the plugged outlet ports of the pump;

FIG. 5 is a fragmentary sectional view taken along line 5-5 of FIG 3 showing the relationship of the plunger slots and the outlet ports;

FIG. 6 is a partial plan view of a fuel injection pump of a type similar to that shown in FIGS. 1-5 but employing a modified form of the present conversion arrangement;

FIG. 7 is a partial sectional view taken along line 7-7 of FIG 6 showing the hydraulic head of the pump and details of the modified conversion arrangement;

FIG. 8 is a partial sectional view taken along line 8-8 of FIG. 6 showing the pump with the plunger distributor slot aligned with an operative outlet port;

FIG. 9 is a sectional view taken along line 9-9 of FIG. 6 showing the distributor slot aligned with an inoperative port;

FIGS. 10 and 11 are fragmentary views respectively taken along lines 1G10 and 11-1I of FIG. 8;

FIGS. 12 and 13 are fragmentary sectional views respectively taken along lines 12-12 and 13-13 of FIG. 9; and

FIG. 14 is a perspective view of the upper end of the pump plunger of the embodiment of FIGS. 6-9 showing the plunger slot arrangement.

Referring to the drawings and particularly FIGS. 1-3 thereof, a fuel injection pump generally designated is partially shown and includes a hydraulic head 22 secured to a main pump housing 24 by bolts 25. The hydraulic head 22 includes a central vertical bore 26 within which a plunger 28 is slidably disposed, the plunger in conjunction with a threaded bore plug 30 defining a fuel distribution chamber 32 in the upper end of the bore. The plunger passes through a sump or spill chamber 34 in the lower part of the hydraulic head and is rotatably and reciprocally driven for delivering fuel to cylinders of an internal combustion engine (not shown).

The pump is driven by the engine by means of the cam shaft 36 which is journaled in the pump housing 24. A cam 38 on the cam shaft having a plurality of cam lobes 40 coacts with roller 42 of tappet 44 and, in conjunction with the helical return springs 46 and 48, effects a reciprocating vertical stroke of the plunger. Rotation of the plunger is effected by means of a vertical quill shaft (not shown) geared to the cam shaft and having a gear at the upper end thereof meshing with the sliding gear 50 on the plunger. The rotation of the cam shaft .36 thus causes both a reciprocation and rotation of the plunger.

The hydraulic head 22 includes fuel inlet ports 52 and 54 on opposite sides thereof to which fuel under pressure is supplied by a suitable fuel supply pump (not shown). The inlet ports 52 and 54 communicate respectively with the fuel supply passages 56 and 58 which in turn open into the fuel distribution chamber 32 when the plunger is in a lowered position. The pressurized fuel passes through the passages 56 and 58 into the fuel distribution chamber when the plunger exposes the passages to the chamber and is pumped sequentially to the cylinders of the engine by the upward strokes of the plunger, the fuel in the chamber being forced through fuel delivery check valve 60 shown in FIG. 3. Fuel flowing through the check valve passes around the valve plunger 62 and through passages 64 and 66 in the plug 68 to an annulus 70 in the plug. The fuel passes from the annulus 70 through passage 72 in the hydraulic head into annulus 74 of the plunger and then into the plunger distributor groove 76, which sequentially communicates with spaced distributor passages 78 in the pump head during rotation of the plunger. Each distributor passage 78 communicates with an outlet passage 80 from which fuel is discharged through outlet port 82' to the cylinders of the engine, the cylinders being connected thereto by means of suitable tubing. The number of ports 82 corresponds with the number of cylinders in the engine for which the pump is originally designed, six in the present instance.

The amount of fuel delivered by the pump is regulated by the position of a control sleeve 84 slidably located on the plunger in the sump 34. The control sleeve is vertically positioned on the plunger by means of a conventional stub shaft and eccentric pin connected with the pump control linkage, none of which is shown in the present drawings in view of its conventional character. A pair of downwardly inclined fuel conduits 86 and 88 extend from the fuel inlet ports 52 and 54 to connect the inlet ports with the sump 34 and thus provide the fuel supply pressure in the sump. The plunger includes an axial bore 90 which extends from the upper end of the plunger to the radial spill ports 92 communicating with the sump 34. When the spill ports 92 are covered by the control sleeve 84, fuel cannot pass from the fuel distribution chamber through bore 90 to the sump. However, when the spill ports clear the sleeve toward the end of the plunger pumping stroke, the pressure in the fuel distribution chamber is reduced to the sump pressure, permitting the check valve 60 to close and stopping further fuel delivery. By adjustment of the vertical sleeve position, the duration of the pumping action and hence the amount of fuel delivered may be accurately controlled. Radial ports 94 in the plunger spaced above the spill ports 92 permit the plunger bore 90 to communicate with the sump during the lower phase of the plunger stroke to assist in filling the fuel distribution chamber.

The pump structure described thus far is a conventional single plunger distributor type fuel injection pump having six outlet ports adapting the pump for use with a six cylinder engine. The pump was designed for operation at engine speed with a four stroke cycle engine. The present invention provides a pump conversion arrangement and method permitting operation with an engine having half the number of cylinders than that for which the pump was originally designed. In the present instance, the six cylinder pump by means of the conversion arrangement may be converted to a three cylinder pump and may be driven either at engine speed for use with a two stroke cycle engine or at one half engine speed for use with a four stroke cycle engine. The conversion arrangement and method by which the conversion may be carried out will now be described in detail.

Referring to the preferred embodiment of FIGS. 15, the six outlet ports as shown most clearly in FIG. 1, are labeled 82a-c in a counterclockwise direction corresponding to the direction of the plunger rotation. The ports 822, f and g are closed by plugs 96 while ports 82a, b and remain operative. As shown in FIG. 4, the plugs 96 include a hollow hexhead bolt 98 within which a cylindrical plug element 100 is mounted to close the outlet passage 80, a resilient seal 102 being provided around the extending portion of the plug element.

The plunger 28 is modified to include an auxialiary slot 104 diametrically opposed from and of the same dimensions as the distributor slot 76, as shown most clearly in FIG. 5. The conversion arrangement and method in the preferred embodiment thus involves simply the plugging of half of the outlet ports in successive order and the provision of an additional slot in the plunger opposed from and corresponding to the distributor slot.

If the pump is to be converted during manufacture, the three plugged outlet ports 82e, and g need not be drilled into the hydraulic head nor are their corresponding passages 78 and necessary. If the ports have already been completed in the hydraulic head, it is of course a simple matter to insert the plugs 98.

In the operation of the converted pump, the reciprocating pumping and rotating distributing action of the plunger continues as before with high pressure charges of fuel being intermittently pumped into the annulus 74 of the plunger in quantities metered by the position of the sleeve 84 and sump 34. The converted pump differs from the conventional pump operation in the manner in which the fuel is distributed from the annulus 74 of the plunger. While normally the fuel passes from the annulus to the distributor slot 76 and then sequentially to the distributor passages 78, in the converted pump the distributor slot, due to the plugging of ports 82e, f and g. would be unable to distribute fuel into the corresponding distributor passages 78e, f and g. However, when the distributor slot is in communication with either of the passages 78e, f or g, the auxiliary port 104 will be in communication with the respective diametrically opposed distributor passage 7811, b or c and since the slot 104 is also in communication with the annulus 74 of the plunger, the charge will be pumped out through the opposed passage and outlet port. For example, as shown in FIGS. 3 and. 5, the distributor port 76 is aligned with the distributor passage 78e of the plugged outlet port 82s. At the same time, the auxiliary slot 104 is aligned with the distributor passage 78a of the operative outlet port 82a and, as indicated by the arrows of FIG. 3, fuel is pumped from the plunger annulus along the auxiliary slot into passage 78a and outlet port 82a.

From the above it can thus be understood that after fuel is pumped sequentially to ports 82a, b and 0 through the distributor slot, fuel will again be pumped through ports 82a, b and 0 through the auxiliary slot 104 and so forth in a uniformly timed manner. The three operative ports 82a, b and 0 thus receive the fuel output which normally would be distributed through all six outlet ports of the pump before conversion and thus receive pumped charges of fuel at twice the pre-conversion frequency. For this reason, the illustrated six cylinder pump designed for operation at engine speed with a four stroke cycle engine may be converted for use with a three cylinder engine for operation at engine speed with two stroke cycle engine operation, or with a three cylinder engine at one half engine speed with four stroke cycle operation.

The conversion arrangement and method may also of course be applied to other pumps having an even number of outlet ports. For example, a four outlet pump designed for use with a four cylinder four stroke cycle engine at engine speed could be converted for use with a two cylinder engine to be operated either at engine speed for two stroke cycle engine operation or at one half engine speed for four stroke cycle engine operation.

The modified embodiment of the conversion arrangement and method shown in FIGS. 6-14 is directed to a fuel injection pump identical with that described above, the corresponding parts of the pumps being given the same identical numbers. In the modified conversion arrangement, alternate ones of the outlet ports 82b, 2 and g are provided with plugs 98 of the type described above. In addition, one of the fuel supply passages 56 is blocked by a plug as shown in FIG. 7. A final modification is the provision of three equally spaced bypass slots 112a, b and c in the upper end of the plunger as shown in FIG. 14. The bypass slots are spaced at and one of the slots is angled at approximately 30 to the distributor slot 76 of the plunger.

In operation, the modified conversion arrangement functions in a somewhat different manner than that of the preferred embodiment in that the fuel charge which would normally be pumped to a blocked outlet is actually not pumped at all due to the communication of one of the bypass slots with the unplugged fuel supply passage 58 to maintain the fuel distribution chamber at the fuel supply pressure and prevent the pumping of fuel through the check valve 60.

In the plunger position illustrated in FIGS. 8, and 11, the distributor slot 76 is indexed with the unplugged outlet port 82a and fuel is pumped from the fuel distribution chamber to the check valve passage 72, annulus 74 and the distributor slot 76 in the normal manner. As shown in FIG. 10, one of the bypass slots 112a in the upper end of the plunger is indexed with the blocked fuel supply passage 56 while the other two slots 112b and 1121: do not communicate with either fuel supply passage. In this plunger position, the bypass slots 112a, b and c thus do not interfere with the normal pumping operation of the plunger.

In the plunger position shown in FIGS. 9, 12 and 13, however, the distributor slot 76 is aligned with the distributor passage 78b leading to the plugged outlet port 82b. As shown in FIG. 12, in this plunger position, the bypass slot 112b is aligned with the open fuel supply passage 58 thus preventing the compression of fuel in the fuel distribution chamber by permitting fuel displaced by the plunger to flow into the fuel supply passage. In this manner, the pump is prevented from pumping fuel when the distributor slot 76 is aligned with one of the distributor passages leading to a plugged outlet port.

In view of the fact that the bypass slots prevent pumping of fuel at alternate outlet ports, the pump in modified form will require the same time for a full pumping cycle as required previously for the six cylinder engine operation. This modified conversion arrangement is thus suited for pumping fuel to a three cylinder engine of the four stroke cycle type with the pump driven at engine speed.

As discussed above with respect to the preferred embodiment, the outlet ports which are plugged and the communicating fuel passages in the hydraulic head need not be drilled in the hydraulic head should the conversion of the pump be planned prior to fabrication of the hydraulic head.

Manifestly, changes in details of construction can be effected by those skilled in the art without departing from the spirit and the scope of the invention as defined in and limited solely by the appended claims.

We claim:

1. In a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotation motion of the plunger, means connecting the fuel distribution chamber with a distributor slot in the plunger, said means providing reciprocating and rotating motion of the plunger effecting a pumping of fuel into said distributor slot by said plunger from the fuel distribution chamber when said distributor slot is sequentially indexed with equally spaced fuel distribution locations of the bore, the improvement comprising means for halving the number of operational fuel distribution locations, said latter means comprising means for blocking fuel flow at half of said locations, and slot means in said plunger in addition to the distributor slot .adapted to receive and discharge into passage means in the hydraulic head the fuel pumped by said plunger when said distributor slot is indexed with a blocked fuel distribution location.

2. In a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, the improvement comprising conversion means for halving the number of operational pump outlet ports, said conversion means comprising means for plugging half of the outlet ports and hence half of the distributor passages, and at least one slot in said plunger in addition to the distributor slot adapted to receive and discharge into passage means in the hydraulic head the fuel pumped by said plunger from the fuel distribution chamber when said distributor slot is indexed with a plugged distributor passage.

3. The invention as claimed in claim 2 wherein said passage means in the hydraulic head comprises the distributor passage diametrically opposed from the plugged distributor passage with which the distributor slot is indexed.

4. The invention as claimed in claim 2 wherein said passage means in the hydraulic head comprises the fuel supply passage.

5. In .a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, the improvement comprising conversion means for halving the number of operational pump outlet ports, said conversion means comprising means for plugging half of the outlet ports to thereby effect a plugging of half of the distributor passages With the plugged passages being disposed With respect to the bore in circumferentially adjacent relation so that the distributor slot sequentially encounters the plugged distributor passages in succession upon rotation of the plunger, and an auxiliary slot in said plunger diametrically opposed from the distributor slot, said auxiliary slot, when the distributor slot is indexed with a plugged distributor passage, being adapted to receive fuel pumped by the plunger into the plunger annulus and deliver the fuel into the distributor passage diametrically opposed from the plugged passage with which the distributor slot is indexed.

6. In a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, the improvement comprising conversion means for halving the number of operational pump outlet ports, said conversion means comprising means for plugging alternate ones of said outlet ports to thereby effect a plugging of half of the distributor passages so that the distributor slot alternately encounters plugged and unplugged distributor passages upon rotation of the plunger, and a plurality of bypass slots in the end of the plunger communicating with the fuel distribution chamber, said bypass slots being angularly disposed with respect to the distributor slot so that one of said bypass slots is indexed with the fuel supply passage when the distributor slot is indexed with a plugged distributor passage, whereby fuel pumped by the plunger when the distributor slot is indexed with a plugged distributor passage is passed through one of said bypass slots into the fuel supply passage.

7. The invention as claimed in claim 6 wherein the number of said bypass slots equals the number of plugged distributor passages.

8. A conversion method for halving the number of operational pump outlet ports in a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, the conversion method comprising the steps of plugging half of the outlet ports and hence half of the distributor passages, and providing at least one slot in said plunger in addition to the distributor slot adapted to receive and discharge into passage means in the hydraulic head the fuel pumped by the plunger from the fuel distribution chamber when the distributor slot is indexed with a plugged distributor passage.

9. The invention as claimed in claim 8 wherein said passage means in the hydraulic head comprises the distributor passage diametrically opposed from the plugged distributor passage with which the distributor slot is indexed.

10. The invention as claimed in claim 8 wherein said passage means in the hydraulic head comprises the fuel supply passage.

11. A conversion method for halving the number of operational pump outlet ports in a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, said conversion method comprising the steps of plugging half of the outlet ports to thereby effect a plugging of half of the distributor passages so that the plugged passages are disposed with respect to the bore in circumferentially adjacent relation so that the distributor slot sequentially encounters the plugged distributor passages in succession upon rotation of the plunger; and providing an auxiliary slot in the plunger diametrically opposed from the distributor slot which auxiliary slot, when the distributor slot is indexed with a plugged distributor passage, is adapted to receive fuel pumped by the plunger into the plunger annulus and deliver the fuel into the distributor passage diametrically opposed from the plugged passage with which the distributor slot is indexed.

12. A conversion method for halving the number of operational pump outlet ports in a fuel injection pump including a hydraulic head having a bore therein, a plunger rotatably and slidably disposed within the bore, a closed end of the bore defining a fuel distribution chamber in conjunction with one end of the plunger, means including a fuel supply passage for introducing fuel into the fuel distribution chamber, means for providing a reciprocating and rotating motion of the plunger, passage means in the hydraulic head connecting the fuel distribution chamber with an annulus in the plunger, a plurality of distributor passages in the hydraulic head radially intersecting the bore at equally spaced circumferential intervals, the distributor passages each leading to an outlet port in the hydraulic head, and a distributor slot in the plunger communicating with the plunger annulus and adapted to sequentially connect the annulus and hence the fuel distribution chamber with the distributor passages during rotation and reciprocation of the plunger, said conversion method comprising the steps of plugging alternate ones of said outlet ports to thereby effect a plugging of half of the distributor passages so that the distributor slot alternately encounters plugged and unplugged distributor passages upon rotation of the plunger; and providing a plurality of bypass slots in the end of the plunger communicating with the fuel distribution chamber, said bypass slots being angularly disposed with respect to the distributor slots so that one of said bypass slots is indexed with the fuel supply passage when the distributor slot is indexed with a plugged distributor passage, whereby fuel pumped by the plunger when the distributor slot is indexed with a plugged distributor passage is passed through one of said bypass slots into the fuel supply passage.

13. The invention as claimed in claim 12 wherein the number of said bypass slots equals the number of plugged distributor passages.

References Cited UNITED STATES PATENTS 2,839,999 6/ 1958 Shallen'berg. 2,958,289 11/1960 Hafele 103l54 X 3,253,546 5/1966 Cook 1032 3,319,616 5/1967 Glikin l03l54 X 3,348,488 10/1967 Wolff 123--l39 X FRED C. MATTERN, JR., Primary Examiner.

W. J. KRAUSS, Assistant Examiner. 

